The invention relates to an apparatus for scraping substances from surfaces, and more particularly to a novel and improved apparatus for manually scraping frost and ice from vehicle windshields and windows. The invention is well suited for scraping frost build-up from automobile windshields, but it is immediately appreciated that the invention finds beneficial use in nearly any application where it is desired to scrape a surface to remove a substance therefrom. For example, the apparatus has utility for scraping paint, varnish and the like from surfaces, as well as for removing rust or other deposits.
Scraper devices typifying the present state of the art are disclosed in U.S. Pat. Nos. 4,275,476 to Hopkins et al., 4,121,316 to Perry, 4,124,915 to Schlicher, and 4,040,140 to Hopkins, et al. The devices disclosed in the foregoing patents, and in the scrapers most frequently encountered in commercial use, generally consist of a handle portion upon which is mounted a single scraper blade. The handle portion is gripped in the user's hand, and the user presses the blade into contact with the surface to be scraped. The manual grip commonly used to grasp most known scrapers is illustrated in FIG. 3 of the '140 patent to Hopkins et al., which also reveals a shortcoming of known devices. Because known scrapers contact the work piece surface along the edge of a single blade, the user must press down to realize the scraping action while simultaneously pulling up to prevent the handle from slamming down to the work piece. Consequently, the user's hand functions essentially as a lever, with the thumb or certain fingers pushing upward to serve as a fulcrum while the remaining fingers and/or palm apply a pressure force toward the work piece. In FIGS. 5 and 6 of the '316 patent to Perry, for example, the user's hand is seen to function as a third-class lever, where the thumb is the fulcrum resisting a downward force to stabilize the scraper in use, while the four fingers apply the downward force against the load (the work piece) and the fulcrum. Other scraper grips employ the user's hand as a simple first-class lever. In all cases, known scrapers pit one set of the user's hand muscles against another set, resulting in rapid fatigue and uneven scraping action. Moreover, due to these inherent inefficiencies, the creating of considerable scraping force demands two-handed use of a scraper, where one entire hand serves as a sort of fulcrum and the other hand supplies the scraping pressure. Two-handed use, however, merely compounds the inefficiencies and further reduces overall control of the scraper tool.
Much of the previous effort in the art has been directed toward providing scraper blades whose edges are shaped, or tipped at specified angles with respect to the surface to be scraped, to maximize performance. The foregoing patents, some of which teach specific blade edge configurations, are all hereby incorporated herein by reference.
The present invention addresses an unmet need for a manual scraper apparatus which removes the user's hand from its role as a lever, and thus permits the user to apply a greater scraping force with less fatigue and more control; and further to provide a bi-diectional scraper which is rugged and highly durable and efficient in use.